Flashing volume and connectivity iocn

The volume and connectivity iocn contuily pop on and off during operation.

Unit was sent out to pocketpctech for replacement of sync connector.

Unit worked fine for about 4 months, then volume icon started flickering on and off, was sent back for repairs. It worked fine for a couple of weeks, then started having the same symptoms again, unit was returned for warrenty work. They were unable to get the unit to repeat the problem again, but rechecked the connections and sent it back. It work ok for several days and started with the same problem again after it was plugged into a gps. This unit is used primarily with anywhere map program in an aircraft, it is plugged in to garmin 35 gps and aircraft power. Can you solve this problem